Circuit breaker



April 14, 1931. c. wElGAND CIRCUIT BREAKER Filed Feb. 3, 1930 PatentedApr. 14, 1931 PATENT OFFICE M WEIGAND, OF CINCINNATI, OHIOV CIRCUITBREAKER Application led February 3, 1930. Serial No. 425,400.

This invention has for an object to produce a circuit breaker which isdesigned to v be used in lieu of the usual or universal fuse plug withwhich electric fuse boxes are equip ed, and especially to be used insuch fuse oXes as are equipped with the screw type of plug of standardsize and designed to occupy sockets of the size of lamp bulb ases.

An object of my invention is also to produce such a circuit breaker aswill permit of restoration to normal conditions the moment a conditioncausing short circuit has been removed froml the line, without having tochange the entire or an portion of the circuit breaker after it hasunctioned to prevent damage to the line following a condition of shortcircuit. v

These and other objects are attained in the 2 circuit breaker describedin the following specification and'illustrated in the accompanyingdrawing, in which:

Fig. 1 is a sectional elevation of my improved circuit breaker,disclosing the breaker in the condition itoccupies when set to carry theline load. Y

Fig. 2 is a plan view of the breaker disclosing its on or load carryingset condition.

Fig. 3 is a plan view similar to Fi 2, but with the protecting cap ortop of the reaker removed.

My breaker in preferred form has a body 5 of cup shape and made ofinsulatin material. At the constricted closed end of t e body is mounteda metal screw base 6, which formsr one terminal of the breaker. This isheld in position by a screw 7 which forms the opposite terminal of thebreaker and is insulated therefrom in the usual manner. This screw holdsa centrally located tubular rod, standard or support 8 upon and withinwhich the vital, elements of the breaker are mounted. At theto of thesup ort a washer 9 is lo- 5 Y cated and eld thereon y being connected,as,

. by soldering, with the upper end of an expansion element 10 extending'from screw 7 to which it is attached. U on and fastened to washer 9 arethe spring gers 10, of the 5 contact terminating the upper end ofelement 10. This element 10 is preferably a wire of such material asGerman silver which will heat and expand readily as to len h when forcedto carry a load above normal or which the line is designed.

Upon support 8 the-bracket 11 is fastened as at a point 12, so that aknife 13 may be pivoted thereto for movement between the fingers ofcontact 10 as shown in Fig. 1. This knife is controlled by a spring 14which would hold it away. from contact 10, as indicated in dotted linesin Fig. 1, were it not for latch keeper or trigger 15 which is pivotedat its lower end to bracket 11 and has a detent 16 which holds knife 13in engagementwith contact 10 as shown. A spring 17 holds trigger 15ieldingly in position to close the circuit. Ilowever, there is a lu 18on trigger 15 which engages a conica collar 19 loosely mounted on suport 8, which functions movement of the kni e 13 to dotted line positionand to disengage the knife for breaking the circuit. This movement attrigger 15 1s caused by upward movement of collar 19 in response topressure of a sprin 20 when the expansion element 10 is heate A metalconnection 21 which is connected with bracket 11, connects with screwbase 6 to complete the circuit therefrom, through bracket 11, knife 13,contact 10, element 10 and screw 7. A slot 22 in closure cap 23 of thebreaker is occupied by extension 24 of knife 13, whereby, in oneposition, the

on position of the breaker will be indicated, and, in the oppositesition, the off condition will be shown. f course, this extension 24will also permit the breaker to be reset by merely moving said extensionmanually from off to on position as soon as the cause ofI a shortcircuit has been removed from the line.

Having thus described my invention what I claim 1s:

1. A circuit breaker comprising a shell, terminals at the base of theshell, a support within the shell, a heat expansible element within thesupport, a collar movable on the support, a knife pivoted onthe support,a contact on the support to be engaged by the knife,|a trigger plvotedon the support to retain the knife in contact-engaged position, a springto move the knife from the contact when released by movement of thetrigger, and means on the support to cause the collar to release thetrigger, functioned by expansion of the element upon passage of excesscurrent through the element.

2. A circuit breaker comprising a shell of insulating material,terminals at the base of the shell, a support of insulating materialwithin the shell and held therein by one of the terminals, a heatexpansible metal element within the support and connected with one ofthe terminals, a collar of insulating material movable on the support, aknife of metal pvoted on the support, a metal contact on the support tobe engaged by the knife, a metal trlg to retain the kni e incontact-engaged position, a spring to move the knife from engagedposltion with the contact when it is released by the trigger, and aspring on the support to move the collar upon expansion of the element,said collar and trigger being associated whereby movement of the collarwill release the trigger.

In witness whereof, I airlx my signature;

CARL WEIGAND.

er pivoted on the support

